Means for heat treatment of metal



Aug. 31, 1937. c. H. 'wA'rRous 2,091,665

MEANS FOR HEAT TREATMENT OF METAL Filed July 6, 193a I INVENTOR flmmvcf Mmqus 1 ATTORNEY Patented Aug. 31, 1937 LUNITED- MEANS FOR HEAT TREATMENT OF METAL f Clarence H; Watrous, Clinton, Conn... assig'nor U V of one-half to Conn.

Frederick A. Schwer, Clinton,

This invention relates to new and improved means for-.heattreatment of metals.

It is the object thereof, among other things, to

assemble metal articles. tobe heat treated in the container I3 may or may not be sealed by spaced relation tov each other and subject the same to a substantially uniform heat.

In the drawing, which illustratesone of the several forms of mechanism that. maybe used in this invention, like numerals of reference indicate like parts inthe several figures;

Figure v1 is afragmentary view of the improved mechanism used in this invention; I p

Figure 2 is a fragmentary sectional view theref; and I,

Figure 3 isan enlarged. fragmentary, view of a portion of the outside container with a support block associatedtherewith.

Heretofore articles to be heat "treated have usually been assembled in a .box with a carbonizer and then placed in a furnace. As the heat generally enters the furnace through the bottom or side. walls thereof, its intensity adjacent to the inlets is greater than at other points. Therefore,

that portion of the box adjacent to the heat inlet points is subject to amore intense heat than are the remaining portions. Likewise the articles are subject to the same unequal heat.

- Attempts have been made to overcome the effect of this unequal application of heat by manually shifting the position of the box within the furnace and successively presenting new faces to the heat inlet points. As space must be providedto permit shifting the boxes, the number of boxes that can be placed within the furnace is thereby limited. Such shifting alsopreventsplacing one box upon the top of other boxes. Thus the capacity of the furnace is considerably decreased. Opening the furnace jdoonto shift the boxes creates a draft and permits the entrance of cold air thatreduces'the temperature of the furnace. The above and other objectionsto the present method of heat treatin'gmetal are eliminated in the invention herein disclosed.

Referring now to the drawing, which illustrates one form of the means adapted to hold, the articles, I indicates, a container, shown herein as substantially rectangular in form and closed by a cover II with the joint between the cover and walls of the container filled with a cement I2, fire-clay, or the like, so as'to form an air-tight joint. I i "Within this container is a similar container I3 which rests upon the blocks I4 in the container I0 and its open side is closed by a cover I5. Each of the blocks I 4 has a platform I6 with projecting the walls of the container II). When assembled,

the container I3 rests on the platforms I6 and thus positioned with an air space or chamber I8 surrounding it.

I The joint between the cover I and the wallsofcement, fire-clay or the like, as may seem most advisable;

in substantially the following manner. First, a layer of carbonizing material, which may be chari coal, ground bone, or the like, is placed on the ,fioor of the container I3, then the articles I9, spaced apart from each other, are placed thereon, and then another layer of carbonizing material of substantially the same depth is placed in the container covering the articles positioned as above. Another group of articles is then placed thereon and this process is continued until the container" I3 is filled. The cover I5 is then positioned and thecontainer I3 placed'within the container Ill supported by the blocks I4, after which the cover ,II is positioned and sealed placed-in the furnace., U As the external heat is transmitted to, the container I3 through the air chamber I8, it is uniform around all sides thereof, irrespective of the varying intensity thereof upon the exterior of the container IIL, touniform heat irrespective of the relative position of the unit within the furnace. Thus the position of the containers within the furnace is" not material and they may be placed either in and the entire unit The articles are thus subjected contact with each other or with a limited open space therebetween sufficient to permita circulationof hot air or on top of each other in tiers to'the limit of the capacity of the furnace.

After the furnace has been loaded, the door thereof .is not opened until the containers are finally removed. After the unit hasbeen subjected to the proper degree of heat for a sufficient length of time, it is withdrawn, the covers of the containers III and I3 taken off and, the articles removed. Thus an increased numberof units may be placed within, the furnace, thelabor of changingthe same is entirely done away with, and the heat within the furnace may be maintained at a more constant temperature because no blasts of cold air are admitted through the door opening.

If charcoal is used as a carbonizer itis preferable that the gas be removed therefrom before being placed in the container.

Rectangular containers. only are shown and used, such as cylindrical, equally as well.

' It is desirable that the articles should be subjected to a uniform heat in order to obtain the best results from the treatment. Under the old above described method the'uneven application described, but containers of other shapes may be 5 of heat resulted in an imperfect heat treatment, while with the application of uniform heat, as

disclosed in this invention, the article is uniform 1y heat treated throughout, and a better article produced.

In practice it has been demonstrated that fine tools, for example razors, cannot be heat treated successfully by the old method but can with the means and method herein disclosed.

Within the scope of the appended claims minor changes and modifications, other than those above suggested, may be made.

What is claimed is:

1. In a unit of the type set forth wherein the parts are assembled and the device loaded before being placed in a furnace and the parts disassembledand unloaded after being removed therefrom, a portable outer container, an inner container for receiving the articles to be treated disposed within the outer container, and means to support the inner container so that its bottom, sides, ends and top walls are each spaced'from the corresponding walls of the outer container whereby to provide heat passages, the bottom of the outer container being formed to seat on and to be freely moved to selected positions on the floor of a furnace, the top of the outer container being formed to receive thereon the bottom of another outer container whereby to enable stacking of the outer containers within the furnace throughout the heating period.

2. In a unit of the type set forth, a portable outer container, an inner container for receiving the articles to be treated disposed within the outer container, means to support the inner container so that its walls are each spaced from the corresponding walls of the outer container whereby to provide heat passages, the bottom of the outer container being formed to seat on and to be freely moved to selected positions on the floor of a furnace, a removable top for the outer container fixed and sealed in position before the unit is placed in the furnace and formed to receive thereon the bottom of another outer container whereby to enable stacking of the units within the furnace throughout the heating period, and a removable top for the inner container spaced from the top of the outer container, the arrangement 'of all of said parts being such that said heat passages are not disturbed or broken down until after the unit has beenremoved from the furnace and the parts thereafter disassembled.

3. In a device of the type set forth; a portable outer container, an inner container for receiving the articles to be treated disposed within the outer container, and means to support the inner container so that its walls are each spaced from the corresponding walls of the outer container, whereby to provide heat passages, the outer container being formed to seat on and to be freely moved about selected positions on the floor of a furnace, and to receive thereon another outer container, whereby to enable stacking of the outer containers within the furnace throughout the heating period.

4. In a unit of the type set forth; a portable outer container having a separable cover; an inner container for receiving the articles to be treated, disposed within the outer container, havwithin the furnace throughout the heating period, the arrangement of all of said parts being such that the covers are positioned before the unit is inserted within the furnace and removed after being taken therefrom.

5. In a unit of the type set forth; a portable outer container having a separable cover with a sealed joint between it and the container; an inner container for receiving the articles to be treated, disposed within the outer container, having a separable cover; and means to support the inner container so that its outside walls are each spaced from the corresponding inside walls of the outer container and thus providing a chamber therebetween, the outer container being formed so as to seat on and be freely moved to any position on the floor of the furnace, irrespective of the relative position of the heat inlet points of the furnace and to receive thereon another similar unit whereby to enable stacking of the units within the furnace throughout the heating period, the arrangement of all of said parts being such that the covers are positioned before the unit is inserted within the furnace and removed after being taken therefrom.

6. In a unit of the type set forth; a portable outer container having a separable cover with a sealed joint of cement, fire-clay or the like, between it and the container; an inner container for receiving the articles to be treated, disposed within the outer container, having a separable cover; and means to support the inner container so that its outside walls are each spaced from the corresponding inside walls of the outer container and thus providing a chamber therebetween, the outer container being formed so as to seat on and be freely moved to any position on the floor of the furnace, irrespective of the relative position of the heat inlet points of the furnace and to receive thereon another similar unit whereby to enable stacking of the units within the furnace throughout the heating period, the arrangement of all of said parts being such that the covers are positioned before the unit is inserted within the furnace and removed after being taken therefrom.

'7. In combination with a furnace; a heat treating unit composed of a plurality of containers. one within the other, and spaced therefrom with an air passage or chamber therebetween completely surrounding the inner of said containers; a cover for each of said containers, the cover for the outer container forming one wall of said air passage or chamber, the inner of said containers receiving thev articles to be treated, the arrangement of all the parts of said unit being such that they are assembled before being placed in the furnace, in any convenient position in relation to each other and to the heat inlet points,

CLARENCE H. WATROUS. 

